IMO the Ferasan ship should be an Escort Carrier, essentially the opposite of the Atrox without losing fighters totally, and an Armitage analogue with a scatter blast console of some kind - maybe a higher yield version of the torpedo turret console with a 180 firing arc?
I'm really not sure what niche a Lethean ship could fill. I assume it would favor Tactical even if it isn't an Escort. Maybe a Sci ship with a lean towards Tac? Or maybe a separating ship of some kind?
As long as one day I can get an Orion tactical cruiser or corvette (Eng Cmdr, Tac Lt. Cmdr) with a hangar, I'll be happy with whatever else rolls out.